It seems to have so far escaped OSNews' notice (if the top few hits for a site-search for 'Steam' is any indication) that Steam for Linux is now in Open Beta; you can get the Linux steam client from steampowered.com. So far, they appear to only be making an Ubuntu .deb available, and the client will require closed-source GPU drivers in order to work.

I expect within 2 years the open source Nvidia support will have overtaken the closed drivers. It's only ATi that seems to be seriously lagging.

Not technically possible with nvidia imho.

NVidia opensource driver team plays permanent catch-up by legally reversing the original driver. They will always be behind in terms of new card support, performance and features, because they will need to see a working upstream driver first, and also get their hands on the hardware.

when it comes to AMD video cards :

AMD opensource team works with the upstream documentation - the company in question actually helps here.

Some of those developers are employed at the company and can develop some things in advance, their code and the official tech documentation for people outside of AMD has to get through lengthy legal review before it can be released out to the public.

The legal part is the biggest problem here. It stalls the documentation release significantly.

Then comes the design of the AMD video cards. More recent models have done away with separate 2D acceleration engine, and 3D engine does all the acceleration (2D, video playback, 3D). Full spec is required to get basic things done, except for maybe setting the resolution and getting things put on the screen, albeit with no acceleration.

Previously, there were separate docs released and things could be incrementally implemented - mode setting, 2D acceleration, video acceleration, 3D acceleration. Nowadays, it's not so easy.

Also, for older cards, there are a lot of problems stemming from undocumented quirks of hardware (check out how long did it take to get HyperZ working due to various unexplained lockups of GPUs, or how often radeon developers stumble upon CS related crashes, even when they have access to official documentation).

If AMD picks up their documentation release effort, so will the development of open source drivers for their cards. Right now developers are bringing up support for subsequent opengl specs up in opensource drivers (radeon drivers are coming close to opengl 3.1 atm) and fixing various performance bottlenecks in existing features.

And when it comes to most recent cards - they are waiting for technical documentation. Which is stuck in legal review.